Oswald s



0. S. PULLIAM.

CYLINDER AND PISTON CONSTRUCTION.

APPLICATION FILED FEB. 27, I920.

Patented May 24, 1921.

A TTORNEYS PATENT OFFICE.

OSWALD S. PULLIAIMZ,

OF NEW YORK, N. Y.

CYLINDER AND PISTON CON STBUOTION.

Specification of Letters Patent.

Patented May 24, 1921.

Application filed February 27, 1920. Serial No. 361,738.

To all whom it may concern:

Be it known that I, OSWALD S. PULLIAM, a citizen of the United States,and a resident of the city of New York, borough of Manhattan, in thecounty and State of New York, have invented a new and Improved Cylinderand Piston Construction, of which the following is a full, clear, andexact description.

The present invention relates to new and useful improvements in pistonconstruction,

and it pertains more particularly to devices of this character commonlyemployed in internal combustion engines; So far as known by me, it hasheretofore been the common practice to make the sides of cylinders andpistons of internal combustion engines straight, and to provide thepiston with piston rings in order that a tight fit between the pistonand the cylinder may be obtained. In constructions above described, thepiston rings very often break and serve to score the interior surface ofthe cylinders. Inasmuch as these cylinders in ordinary forms are cast enbloc, the damage done to any one cylinder renders the entire setinoperative, thus necessitating the re-boring or replacing of theseveral cylinders,

In the present invention, the cylinders are constructed in such a mannerthat they carry the'rings instead of the pistons. By this constructionshould the rings break,

the greatest damage which could be done would be a scoring of thepiston. Since the pistons are separately carried by the crank shaft, asingle piston when it becomes damaged may be replaced by a good onewithout the necessity of replacing the remainder of the pistons which goto make up the engine.

In the present invention the walls of the cylinder and the walls of thepiston are slightly tapered in such a manner as to provide for arelatively snug fit between the piston and the cylinder when the pistonis at the extent of its upward stroke, at which time it is desirable toobtain this relatively snug fit Referring to the drawings- Figure 1 is alongitudinal sectional view of t e cylinder, the shown in elevation;

Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 1.

Referring to the drawings by reference piston thereof being character, 5designates the cylinder, and 6 the piston. In the present instance but asingle piston and cylinder have been shown since this is deemed adequateto properly set forth the principles of the invention. The innerdiameter of the cylinder 5-at the point designated by the referencecharacter 7 is slightly reduced as compared to the diameter-of thecylinder 5 at that point indicated by the reference character 8 or thelower portion of the cylinder, and the upper end of the piston 6 asdesignated by the reference character 9 is of a slightly smallerdiameter than its lower portion designated by the reference character10.

Adjacent its lower open end the cylinder 5 is provided with two or moreconcentric channels 12, and mounted in each of these channels 12 is aring 13. These rings 13 are of the cdmmon resilient type, and areadapted to surround the piston 6 1n sliding contact therewith in such amanner as to provide a gas-tight joint between the piston and thecylinder.

The operation of the device is as follows: Upon the down stroke of thepiston 6, the reduced diameter thereof will move to a point where itwill be engaged by the rings 13. Upon the up stroke thereof, when thepiston has reached the limit of said up stroke, the upper end 9 thereofwill be of an exterior diameter substantially equal to the interiordiameter of the portion 7 of the cylinder 5 and will form a snug jointtherewith. At this point, the enlarged diameter of the piston engagesthe rings 13 and inasmuch as said rings are of an internal diameterequal or substantially equal to the reduced diameter 9 of the piston 6,the enlarged diameter of the piston will tend to expand said rings,thereby causing a tight joint between said rings and piston.

From the foregoing it will be seen that the present invention provides acylinder and piston construction more particularly adapted for internalcombustion motors in which it is practically impossible to subject theinner surface of the cylinder to destructive or mutilating scores whichcommonly exist in the form of broken piston rings.

Having thus described the invention, what is claimed as new is:

1. A cylinder and piston construction comprising a cylinder having alongitudinal taper, a plston having a corresponding longitudinal taper,and means for forming a tight joint between said piston and the walls ofsaid cylinder.

2. In a cylinder and piston construction, a cylinder having a taperedbore, a piston having a correspondingly ta red exterior diameter, andmeans carried y the cylinder and adapted for interengagement with thepiston to form a gas-tight joint therebetween.

3, In a cylinder and piston construction, a cylinder having a taperedbore, a piston having a correspondingly tapered diameter, and meanscarried by the cylinder and adapted to be operated by the increaseddiameter of the piston to render a tight joint between said iston andcylinder;

4. A cyh'n er and piston construction comprising a cylinder having awork1ng space, one end ofwhich is reduced with respect to, the oppositeend, and a piston sha liggll1 correspondingly to the shape of the wor gspace of said cylinder, whereby said piston forms a gas-tight joint withthe walls .of the working space of said cylinder in one positiontherein. v

5, A cylinder and piston construction com prising a cylinder having aworking space,

one end of which is reduced in diameter, a

piston havin a corresponding taper whereby a gas-tig t joint is formedbetween the Walls'of the piston and the walls of the c lin-

